1. Field of the Invention
The present invention generally relates to a gateway for interconnecting an ad-hoc network and an infrastructure network and methods for discovering and registering a service provider using the gateway. More particularly, the present invention relates to a gateway which discovers a requested service in an ad-hoc network or an infrastructure network upon receiving the service request and methods for discovering and registering a service provider using the gateway.
2. Description of the Related Art
With the advance of communication technologies, not only wired networks but also wireless networks are established and are in use. The wireless network environment can be divided into an infrastructure network and an ad-hoc network.
The infrastructure network is a communication network that uses access points. The access points relay communications between terminal devices that operate in the infrastructure mode.
The ad-hoc network is a communication network where a plurality of terminal devices independently resides in a space and performs one-to-one communication with devices within their recognizable range. A terminal device operating in the ad-hoc mode can act as a server or a client.
It is possible to variously implement the type of terminal devices in the infrastructure network or the ad-hoc network, respectively. For example, devices, such as general desktop personal computer, notebook computers, printers, facsimile machines, mobile phones, and personal digital assistants (PDAs), can establish the wireless network environment. Each terminal device provides a specific service. For instance, a printer provides a printing service, and a facsimile machine provides a fax service.
Meanwhile, there is a difference between the infrastructure network and the ad-hoc network with respect to how to use the services provided from the terminal devices connected to the respective networks due to network characteristics.
Specifically, in the infrastructure network, service information provided from the terminal devices is integrated and managed using a service repository. To manage service information, the service repository pre-stores a lookup table which records information relating to an address and a service of each terminal device. In further detail, upon receiving a service request (SREQ) packet from a certain terminal device, the service repository responds with a replay packet containing information relating to a terminal device which provides the requested service, that is, a service provider by referring to the lookup table. The terminal device, upon receiving the reply packet, is provided with the service by communicating with the service provider.
By contrast, in the ad-hoc network, each mobile node provides service using a peer-to-peer communication. In specific, a mobile node that requests service, that is, a service requester broadcasts a SREQ packet over a certain range. If a mobile node providing the requested service is present amongst neighboring mobile nodes that receive the broadcast SREQ packet, the mobile node, that is, a service provider sends a reply packet to the service requester. Alternatively, if the mobile node receiving the SREQ packet holds information relating to the service provider, the mobile node sends a reply packet containing the information relating to the service provider, to the service requester. Hence, the service requester can be provided with the service from the service provider.
As discussed above, the service delivery system differs according to the infrastructure network and the ad-hoc network. As a result, the mobile node communicating in the ad-hoc mode cannot use the service provided from the node communicating in the infrastructure mode, and vice versa. Thus, the service availability is deteriorated in the environment established with various terminal devices.